The regulatory approvals of immune checkpoint inhibitors in China and the United States: A cross-national comparison study

Immune checkpoint inhibitors (ICIs) are currently one of the most popular treatment methods for cancers. Several ICIs have been approved in China and the United States. We created a database of approved ICIs by extracting the information of interest from the drug labels and reviewing documents disclosed on the official websites of the US Food and Drug Administration (FDA) and the Center for Drug Evaluation (CDE) of the China National Medical Products Administration (NMPA) and compared the difference between the marketed ICIs in China and the United States regarding the number of indications, tumor types, review time, treatment setting, and so forth. Until June 30, 2022, 9 and 15 ICIs had been approved for 86 and 58 indications in the United States and China, involving 20 and 14 types of tumors, respectively. The correlation between indications and disease incidence was higher in China (r = 0.64) than in the United States (r = 0.45). About half of the indications were approved as first-line therapies in combination with chemotherapy, target therapy, or immunotherapy. Over 30% of indications were approved under accelerated or conditional approval in the two countries. A shorter regulatory review time was required by the FDA (median:181 days) compared to the NMPA (median: 279 days) for the new indication approval. Five ICIs marketed in China were approved by the FDA before the NMPA, with the median launch delay for the same indication of 344 days in China. A differentiated clinical development program that focuses on meeting unmet needs may bring new success for subsequent ICI products.     

The cell cycle and induction of apoptosis in a hamster fibrosarcoma cell line treated with anti-cancer drugs: Its importance to solid tumour chemotherapy*

The induction of apoptosis by anticancer drugs and its relationship to stages of the cell cycle was studied in cells derived from a solid tumour; a highly malignant hamster fibrosarcoma (Met B). Asynchronously proliferating cells were treated with a wide variety of agents such as actinomycin-D, 1--D-arabinofuranosyl cytosine, camptothecin, cisplatin, cyclophosphamide, daunorubicin, 5-flurouracil, 6-mercaptopurine, hydroxyurea, ionomycin, methotrexate and vincristine. With the exception of cyclophosphamide and hydroxyurea, a 36 h exposure to these drugs resulted in inhibition of cell growth and apart from cyclophosphamide, hydroxyurea, 6-mercaptopurine and cisplatin the induction of apoptosis. Studies using a decreased concentration of drug and exp osure time (12 h) followed by examination of cells using flow cytometry indicated that most drugs were capable of affecting cell cycle progression without induction of apoptosis. However when cells were synchronised at G₀/G₁, S and G₂/M phases and then exposed to these decreased concentrations of drug apart from 6MP an HU, apoptosis was observed and for the majority of drugs it took place in the same phase in which progression through the cell cycle was blocked by the drug. Cells synchronised in G₀/G₁ phase were more susceptible to methotrexate, whereas S-phase cells were more susceptible to camptothecin and 5-flurouracil and G₂/M phase cells more susceptible to actinomycin D, 1--D-arabinofuranosyl cytosine, daunorubicin and cisplatin. In contrast, vincristine blocked cells in G₂/M phase but exerted its apoptotic effect in S-phase cells, ionomycin had no effect on the cell cycle, but G₂/M cells appeared to be more susceptible to the effect of this drug. These data indicate that entry into apoptosis by this fibrosarcoma may occur at any point in the cell cycle. They also demonstrate a correlation between the action of some anticancer drugs on the cell cycle and the subsequent induction of apoptosis which may be useful in chemotherapeutic design.